Racket stringer



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w. cIBIcKEL RACKET STRINGER Dec" 11?, was.

Fil d Aug. 20, 1934 INVENT BY WW; afizowl ATTORNEY.

Patented Dec. 17, 1935 UNITED STATES PATENT OFFICE RAGKET STRINGER Willis 0. Bickel, Oak Park, Ill.

Application August 20, 1934, Serial No. 740,552

7 Claims. (Cl. 265-1) This invention relates to a tool intended for stringing rackets and the like and particularly intended for stringing lawn tennis rackets.

The objects of this invention are to provide a tool for tightening racket strings whereby they may be tightened with a uniform or predetermined tension; to provide a racket stringer adapted to be applied to the rim of a racket for tightening the strings whereby the strings may be tightened with little or no deformation of the rim; to provide a tool of this character with resilient tension means adapted to be adjusted to provide different tensions when the indicating member is moved to a predetermined indicating position; to provide a tightening tool for stringing rackets whereby they may be properly strung by inexperienced persons; to provide a tool which may be conveniently used without interfering with the awl or pick used for temporarily holding 2() the strings and to provide such other uses and novel features as will be described more fully hereinafter.

In the accompanying drawing illustrating this invention:

25 Fig. 1 is a top or plan view;

Fig. 2 is a sectional view taken on the line 22 of Fig. 1; Fig. 3 is a sectional view taken on the line 3 -3 of Fig, 2, and Fig. 4 is a side view illustrating the method of using the tool.

30 In the particular form of the invention as shown in these drawings I provide a saddle or bracket 6 having a substantially U-shaped portion with side flanges 1 adapted to fit over and rest against the hoop or frame of the racket.

3.3 A strip or pad 8 of yielding or resilient material such as rubber is preferably positioned in the bottom of the groove to rest on the outer periphery of the frame and to prevent slipping as well as marring of the frame. The bracket 6 has two 40; outwardly projecting arms 9 between which is pivotally mounted a rotatable head or frame It! by means of pivots or screws H. The head H] has an outwardly extending handle I2 which is preferably formed integrally therewith and has 4-5. a recess or chamber H5 at the inner end thereof.

A string engaging member or lever l4 fits in a slot or recess in the head It and is supported on a pivot l 5 which engages with lugs or projections 5 on the sides of the head.

The string engaging member M has a flanged section I! extending beyond the pivot 15 and providing a curved plate or surface over which the string is to be drawn. The fastening means for the string comprises two laterally projecting pins l8 and I9 which are preferably formed integrally with the lever and which are arranged at a short distance from the curved plate ll. These pins co-operate with a post which has a tapered slot 2| for receiving and holding the free end of the string. This post extends at substantially a 5 right angle from the pins l8 and I9 as will be seen from Fig. 2.

The lever I4 has one branch on which the pins and post are formed which branch has a stop 22 which is adapted to engage with the adjacent 10 surface 23 of the head in order to limit the movement of the lever in one direction. The stop 22 is conveniently arranged so that if necessary it may be filed in order to adjust the final position of the lever. 15

This lever also has another branch or arm 24 for engagement with the tension measuring means. This measuring means includes a cap or thimble 25 which is slidably mounted in a hole or guideway 26 in the head Ill. The outer end 20 of the hole is threaded at 2? for receiving an adjusting screw 28. A spring 29 is interposed between the thimble 25 and the inner end of the screw and is adapted to resist the arm 24 in one direction as shown in Fig. 2. The outer portion 25 of the wall adjacent to the end of the hole 26 has an opening 30 with registering marks 3| at the sides thereof.

The outer smooth portion of the periphery of the screw 28 is provided with figures 32 for in- 30 dicating the pressure, which figures with marks accompanying the same are adapted to register with the hole 30 to indicate the tension or resistance of the spring when the screw is adjusted to the corresponding position.

The arm 24 terminates in an arcuate end portion 33 having a gauge mark 34 thereon. The adjacent wall of the head I!) has an aperture 35 with indicating marks 36 which are adapted to register with the mark 34 when the string engag- 40 ing member I4 is moved to the proper position to correspond with the desired tension indicated by the figure 32 when brought to register with the hole 30.

In the stringing of a racket it is desirable to have the tension of the strings as uniform as possible which is difficult of accomplishment by the ordinary hand methods commonly used. It will also be noted that in pulling the string through the holes there is apt to be considerable friction, particularly if. the string is pulled out of alignment with the hole, as may occur in using other types of tools, so that even if the pull on the string outside of the frame is measured, it is impossible to determine the actual tension placed on the portions of the string within the frame. By means of my improved tool the portion of the string exteriorly of the frame is kept closely in alignment with the hole so that the resulting tension may be accurately determined.

In the operation of the stringer the saddle 6 is placed on the racket frame 31 as shown in Fig. 4 and the free end of the string 38 is brought out over the curved engaging end I! and fastened to the fastening members I8, l9 and 20. The arrangement of fastening will depend in part upon the side of the frame to which the tool is applied but, as shown in this figure, the free end is preferably passed around the under side of the post 20, then around the pin I9 and crossed in front of the post and then brought under the pin l8 and the free portion pressed into the tapered slot 2| which holds it securely in fastened position. At this time the handle is swung forwardly so that the curved string engaging portion H is swung in toward the frame. The handle I2 is then swung around as indicated in Fig. 4 until the tension on the spring brings the mark 34 into alignment with the marks 36 at the sides of the hole 35, at which time the tension on the spring will correspond with the numeral 32 in the hole 30. It is of course understood that the screw is calibrated to give the proper tension when the numerals 32 are brought to register with the opening 38. For instance, when the numeral 54] is in view as shown in Fig. 1, the tension will be 50 pounds when the lever 24 is swung on its pivot against the tension of the spring until the mark 34 registers with the marks 36. At this time an awl or pick is inserted in the hole in the frame to fasten the string in position in the usual manner. The string may then be released from the tool and the operation continued as will be readily apparent. It will be readily seen that by means of my improved tool, rackets may be quickly and easily strung in a satisfactory and uniform manner by persons having comparatively little skill. Furthermore, by adjusting the spring by means of this adjusting screw, any desired tension may be provided and it is only necessary for the operator to watch the indicating mark 34 through the side opening 35 to determine when the proper tension has been reached. It will of course be apparent that these marks and sight openings may be placed on both sides of the tool for convenience in operation when the tool is applied to one side or the other of the racket frame.

While I have shown and described a preferred form of my invention it will be noted that changes may be made to adapt the same for use for stringing different kinds of rackets or similar devices, and therefore it is the intention that the invention should not be limited to such specific form except as set forth in the following claims in which,--

I claim:

1. A racket stringer comprising a bracket adapted to engage with the frame of the racket to provide a fixed fulcrum, a head pivotally mounted on said bracket and having a handle, a string engaging member pivotally mounted in said head, resilient means tending to resist turning movement of said member, and means for adjusting the strength of said means.

2. A racket stringer comprising a saddle adapted to engage with the racket and to remain in relatively fixed position thereon, a head pivotally mounted on said saddle and having a handle for swinging. the same and having a threaded recess, a string engaging member pivoted in said head, said member having a curved portion over which the string is drawn and having means for fastening the end of the string, a spring mounted in said recess and engaging with said member to bias the same so as to resist the pull on the string, a screw engaging with the threaded opening in the head and with said spring, said screw being provided with calibrations readable relative to a portion of said head to indicate the force exerted by said spring when the string-engaging member is moved to a predetermined position, and means on said member and said head for indicating such position of the string-engaging member.

3. A tool for the purposes described, comprising a bracket having a channel portion for engagement with a racket, arms projecting outwardly from said bracket, a head pivotally mounted on said arms and having a sight opening therein, a handle for swinging said head, a lever pivoted at one side of the head and having a curved projection over which the string may be brought, pins extending laterally from the lever adjacent to the curved portion, a post with a tapered slot therein for fastening the string extending from the lever adjacent to said pins, an arm projecting from said lever, a mark on said arm, marks on the head with which said mark on the arm is adapted to register for indicating the proper limit of movemet of the lever, said head having a bore therein at substantially right angles to the arm, a screw engaging with said bore and a spring interposed between the screw and the arm, said screw having calibrations thereon adapted to register with said sight opening in the head to indicate the pull on the string when the screw is adjusted to different positions.

4. In a too-l for stringing rackets, the combination of a bracket having a channel portion for engagement with the frame of the racket, a re- 40 silient pad in said channel portion, a lever pivot ally mounted in said bracket, a string engaging member pivotally mounted in the lever, said string engaging member having a curved portion over which the string is drawn and having a plurality of projections adjacent to said curved portion for fastening the string, one of said members having a tapered slot therein, a stop on said member adapted to engage with the lever to limit the movement in one direction, an adjustable tension means co-acting with the lever and the string engaging member for indicating the pull on the string when the lever is swung to tighten the same.

5. In a tool for tightening the strings in stringing rackets or the like, the combination of a saddle adapted to engage with the frame of the racket and to remain in relatively fixed position When a string is being tightened, an operating member pivotally mounted on said saddle, said 1 member comprising a chambered head with an outwardly projecting handle, a. bellcrank lever pivoted at one side of the head and having an outwardly extending curved portion for receiving the string, string fastening means on one branch of said lever adjacent to the curved projection, a thimble slidably-mounted in the head and engaging with the other arm of said lever, an adjustable screw mounted in the head, a spring interposed between the screw and the thimble, means for indicating the tension on the spring when the screw is adjusted, and indicating means for indicating the proper relative position of the lever with respect to the head to give the desired tension on the string which is being tightened.

6. In a tool for tightening strings for rackets, the combination of a bracket adapted to fit over the frame of the racket, a resilient pad in said bracket adapted to prevent sliding of the bracket on the frame, a chambered head pivoted in said bracket and having an outwardly projecting handle, a string engaging lever pivoted at one side of the head and having an outwardly extending curved portion for engagement with the string, oppositely disposed pins adjacent to the curved portion and a post having a tapered slot therein adjacent to the pins, said pins and post serving as fastening means for the string, said lever having an arm projecting into the chamber in said head, a thimble slidably mounted in the chamber and engaging with the arm, a compression spring engaging with the thimble, an

adjusting screw mounted in the head and engaging with said spring, marks on said screw to indicate the resistance of the spring when the screw is adjusted, said head having a sight opening with which said marks are adapted to register, and indicating marks on said lever, said head having sight openings with which said indicating marks are adapted to register, said last named marks serving to indicate the proper position of the lever to give the desired tension on 10 the string which is being tightened.

7. A racket stringing device comprising a bracket adapted to engage with the frame of the racket to provide a fixed fulcrum, a head pivotally mounted on the bracket and having a handle, 15

a string engaging member pivotally mounted in said head, and resilient means tending to resist the turning movement of said member.

WILLIS C. BICKEL. 

